"The state’s current laws deny its gay and lesbian citizens their fundamental right to marry and, in so doing, demean the dignity of these same-sex couples for no rational reason," the judge wrote in his opinion.

The state began handing out marriage licenses after the judge's ruling, but now gay couples will have to put their wedding plans on hold. If the 10th Circuit Court of Appeals affirms the judge's ruling, then gay marriage will be legal in Utah. It's likely that whichever side loses its case in Utah will ask the Supreme Court to weigh in on the constitutionality of gay marriage.

If the U.S. Supreme Court accepts the Utah case, it could be the first opportunity for the high court to decide whether bans on gay marriage are constitutional.

While the Supreme Court heard two huge gay marriage cases last term, it did not actually issue a decision on whether gay marriage bans are constitutional. One of those cases involved Section 3 of the federal Defense of Marriage Act, or DOMA, which denied federal benefits to married same-sex couples.

The Supreme Court struck down Section 3 as unconstitutional, finding the law "contrives to deprive some couples married under the laws of their State, but not others, of both rights and responsibilities, creating two contradictory marriage regimes within the same state."

Anti-gay marriage advocates brought the case to the U.S. Supreme Court. The high court ruled they didn't have standing to bring the suit, so it dismissed the suit and effectively kept gay marriage legal in California. That ruling didn't affect other states, though. If the Supreme Court actually has a chance to rule on the constitutional issue at the heart of the Utah fight, that case could have much broader ramifications.